This is a good thing for fans of flavored coffee as the beans absorb the coffee flavoring syrups and oils that are used to make flavored coffee. However, if given the chance, coffee can also absorb other things like the flavor of seafood or the moisture that your freezer produces. This moisture will in turn deteriorate the coffee and even make it taste like, well... like a freezer.
When coffee is roasted, the beans release their oils and essences to give the coffee its distinct flavor. You'll notice these oils are more prominent on dark-roasted coffee and espresso. When you break down these oils by freezing, you are removing the flavor.